“Pleasantly surprised at his motor, because I thought it was pretty good,” coach Brad Stevens said.

Sullinger felt the same way: surprised.

“Yes, very. I didn’t think I was going to make it through practice,” he said. “Being six months off and then trying to get back in the swing of things, that’s really, really tough.”

Still, Sullinger said he’s “not even close” when it comes to conditioning. “I’m nowhere near where I need to be,” he said.

He also said he’s “very rusty.” With what? “Everything,” he said.

“Timing, footwork, where I need to be on the court, just trying to figure out what I can do,” he said. “I had back surgery, now I’ve got to modify some things and see what I can do well.”

Sullinger, who played in 45 games his rookie season, said he trusts his back and has reached the point where he can move without worrying he might reinjure it.

“I passed that point, mentally, in August,” he said. “The first time I got back on the court, I was really nervous about moving, but now, I’m taking charges again, moving.”

Early riser

On the eve of his first training camp, Avery Bradley was a little nervous.

“I probably woke up at, like, 6 this morning. I was excited,” the guard said, later admitting to a few jitters during the morning practice.

Bradley is entering his fourth season, but this is his first training camp, as health issues and the NBA lockout limited him in previous ones.

And during the sessions, he played point guard, a role he’ll likely play while Rajon Rondo
recovers from knee surgery.

Bradley said that while there was plenty that was new, Stevens made him and the other players feel comfortable.

“The plays that I run, it’s kind of like I play point guard, but everybody makes plays for each other,” he said.

When comparing this system with the one the Celtics used under
Doc Rivers, Bradley said the two are miles apart.

“It’s everybody,” he said. “Everybody is interchangeable. It’s a lot different. I’m not the one always initiating the offense.”

Bradley also enters camp coming off some recent emotional events: the birth of his first son, Avery Bradley III, and the death of his mother.

Bradley described being a father as “amazing.” When asked if basketball was a sort of therapy for him following his mother’s death, he said, “It’s always been therapy.”

Fighting words

One of the mystery men for the Celtics during the offseason is Brazilian center Vitor Faverani, who is the only true center on the Celtics’ roster.

When asked to describe his playing style during media day, some of the first words out of the 6-foot-11-inch, 260-pounder’s mouth were “I like to fight.”

(His full answer, for the record: “My playing style, I don’t know, I like to fight, play in the paint, rebounds, dunks, pick and rolls.”)

It was a fitting answer for a player whose nickname is “El Hombre Indestructible” (The Indestructible Man). He earned that moniker for his brutish playing style.

Celtics team director of player personnel Austin Ainge added of Faverani, “He loves to hit. He’s physical. He comes in and he makes things happen and instigates contact.”

Faverani played last year for Valencia Basket Club of the Spanish ACB League, averaging 9.3 points and 4.6 rebounds in 23 games. It’s unclear what role he’ll play for the Celtics this season — or how ready the 25-year-old is for the NBA level.

“That will sort itself out,” Stevens said. “I think the first step will be how he compares to the other bigs coming out of training camp, and that question may be sooner rather than later. But it’s certainly undetermined right now.”

Stevens said he thought Faverani played well on his first day of camp, and Stevens said that aside from size, Faverani can shoot the ball pretty well.

“He made a three, although he did it off the glass,” he said. “He might have called it, but I couldn’t understand him if he called it. But he was good. And he did a good job defensively. [Assistant coach] Ron Adams has spent a lot of time with Vitor and really done a nice job with him.”

Faverani, who signed a three-year deal with the Celtics worth about $6 million, also said it was an easy decision to join the Celtics after playing professionally overseas.

“It’s the best team in the NBA,” he said. “It’s very important in the NBA. When I came here for perhaps my first time, I think, ‘I want to stay here forever.’ ”

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